The alternative names that parents use to refer to their prepubescent daughter's genitals never cease to amaze me.
That said, I'm not sure what to suggest.
With my kids we always called it a vagina. It seemed a bit torturous to try to get my 3 year old daughters to identify the multitude of distinct areas on the female anatomy. "Mommy, my labia majora itch" doesn't roll off the tongue. But calling the entire thing a vagina is less than accurate.
So I get a chuckle out of the dads that come in saying "She's got bumps on her bug."
I knew what he was talking about. She knew what he was talking about. Is calling it a "buh-gina" any better?
Maybe I should have gone with pitty-pat...